PEROVSKITE TO ANTIPEROVSKITE IN ABF3 COMPOUNDS

Results of static energy calculations using, ab initio Gordon-Kim potentials for ABF3 perovskites, where A is an alkali metal ion and B is an alkaline earth metal ion, are presented which demonstrate the role of the relative size of A and B in determining the ground state. Our results point out that the antiperovskite structure, obtained by interchanging the positions of A and B, can be viewed as a highly distorted perovskite structure, or vice versa. The energetics of NaCaF3, a predicted ferroelectric, are analyzed in detail. © 1990, Taylor & Francis Group, LLC. All rights reserved.